恢复年限、林下植被及季节对马尾松林土壤氮转化的影响

侵蚀红壤区植被恢复能有效防治土壤侵蚀,改善生态环境。提高侵蚀退化地土壤氮矿化潜力、增加氮有效性是改善贫瘠土壤植被生长发育的关键途径,对恢复侵蚀地生态系统具有重要意义。采用顶盖埋管培养法研究了不同恢复年限(Y0、Y16、Y34))不同芒萁处理的马尾松林土壤净氮矿化量和净氮矿化速率的季节变化特征,分析了植被恢复年限、林下植被覆盖及季节变化对土壤氮矿化的交互影响。结果表明,植被恢复能使侵蚀退化地土壤养分条件得到改善。不同恢复年限马尾松林净氮矿化最高值出现在夏秋季,而在春季为负值。植被恢复能使土壤净氮矿化量显著增加,且净氮矿化过程以氨化作用为主。净氨化速率与净矿化速率具有相似的季节变化,硝化速率随着恢复年限增加季节变化减小。林下裸露地净氮矿化量及速率低于芒萁覆盖地,且去除芒萁可以降低净氮矿化量及速率。方差分析表明,恢复年限、季节变化及其交互作用能显著影响土壤净氮矿化量及矿化速率(P<0.001),而芒萁处理未能达到显著水平(P>0.05)。马尾松林土壤氮转化过程季节变化明显,林分管理应按季节变化进行,林下芒萁覆盖对侵蚀退化地马尾松林土壤氮恢复具有重要作用。     

子午岭林区浅层滑坡侵蚀与植被的关系——以富县“7·21”特大暴雨为例

以2013年陕北富县"7·21"特大暴雨滑坡侵蚀灾害为对象,通过调查暴雨侵蚀区典型小流域植被条件及滑坡特征,测定滑坡壁不同土层的根系重量、土壤孔隙度、土壤容重等指标,研究子午岭林区暴雨滑坡侵蚀与植被根系的关系。根据不同类型植被根系深度和滑坡侵蚀特征(侵蚀深度、滑动面宽度及长度,滑坡体体积、滑动距离等),可将林区暴雨滑坡侵蚀划分为三类:以草本植被为主的A类滑坡,以灌丛植被为主的B类滑坡,以乔本植被为主的C类滑坡。结果表明,三类滑坡侵蚀的侵蚀深度与其对应植被类型的根系深度相近,且植被及其根系会加剧滑坡侵蚀的发生。在此次暴雨滑坡侵蚀中,滑坡侵蚀强度受植物根系重量、土壤孔隙度、土壤容重等因素的共同影响,但根系重量对滑坡侵蚀强度的影响占主导作用,通过建立二者之间的关系式发现,根系对滑坡侵蚀的贡献率超过80%。不同植被类型的滑坡侵蚀深度不同,且滑坡侵蚀强度也存在差异,表明植被根系不仅具有塑造滑坡侵蚀特征的作用,而且会影响滑坡侵蚀的强弱程度。在强降水基础上,特别是当降水量达到诱发滑坡灾害发生的临界值时,植被及其根系会加剧滑坡侵蚀的发生。在今后工作中,要因地制宜合理配置各类植被,同时结合其它措施,以便提高植被防治水土流失的作用,更好地发挥植被的水土保持效益。     

福建红壤区不同侵蚀强度马尾松林地土壤营养元素变化特征

采用野外调查和室内分析的方法对福建红壤区不同侵蚀强度马尾松林地土壤营养元素动态进行研究,以揭示红壤侵蚀区不同侵蚀强度对马尾松林地土壤营养元素的影响.结果表明:除速效磷以外,侵蚀强度显著改变了土壤有机质、碱解氮、全钾、速效钾的含量以及土壤pH.土壤有机质和碱解氮在中度侵蚀马尾松林地含量最高,随着侵蚀强度的增加植被覆盖减少,土壤有机质和碱解氮显著降低.土壤全钾和速效钾含量随着侵蚀强度的增加而显著增加,土壤速效磷随着侵蚀强度的增加没有显著的变化.土壤pH值随着土壤侵蚀强度和土壤深度的增加而显著增加.皮尔逊相关关系分析表明:有机质与碱解氮、全钾和pH显著相关.灰色关联度分析表明:除侵蚀强度对营养元素和pH有显著影响外,坡度对土壤营养元素和pH影响较大;覆盖度对有机质、碱解氮和速效磷影响较大.因此,植被恢复和植被生境的综合治理是红壤侵蚀区生态恢复与重建的有效途径.     

侵蚀退化红壤自然恢复下土壤生物学质量演变特征

为了探讨严重侵蚀退化红壤区自然植被恢复过程中土壤生物学质量演变特征,对南方严重侵蚀退化红壤自然植被恢复的4个演替阶段（裸地,地衣地,苔藓地和草地）,以及该地区人工马尾松林地的土壤微生物量、酶活性和线虫数量进行了比较研究。结果表明：在侵蚀红壤自然恢复过程中土壤生物学性质演变特征明显。在恢复初期,地衣和苔藓对土壤生物学性质的改善主要体现在土壤表层。在0～2cm土层地衣地土壤微生物量碳、氮、蔗糖酶和脲酶活性高于裸地,但差异不显著;苔藓地表层微生物量氮、脲酶和酸性磷酸酶活与人工马尾松林地已无显著差异,表明苔藓地是严重侵蚀退化红壤自然恢复过程中土壤质量改善的重要阶段。裸地、地衣地和苔藓地土壤线虫恢复程度低于微生物量和酶活性。草地土壤微生物量碳、氮和3种酶活性以及线虫数量则显著高于自然恢复初期各阶段。与人工恢复林相比较,自然恢复草地表层土壤生物学质量优于人工马尾松林地,但对深层土壤的改善效果不如林地。相关分析表明自然恢复过程中土壤微生物与酶活性的改善程度比较一致,而土壤线虫对自然植被恢复响应与微生物和酶活性不尽相同。     

中亚热带植被恢复过程中崩岗土壤性质分异特征

崩岗是我国南方红壤丘陵山区坡面沟道侵蚀后期发育而成的侵蚀地貌,探讨崩岗系统植被恢复过程中不同部位土壤性质分异特征,对揭示强度侵蚀环境下土壤环境效应以及指导崩岗区生态恢复具有重要借鉴意义。以闽西南长汀县濯田镇黄泥坑崩岗群内植被盖度分别为2%、20%和95%的3处毗邻崩岗为研究对象,研究各崩岗集水坡面、崩壁(顶部、中部及底部)、崩积体(上部和下部)和沟道出口等部位0—20 cm土壤理化性质的分异特征。结果表明:土壤容重、粉粒、pH、速效养分含量均表现为崩岗Ⅲ崩岗Ⅱ≈崩岗Ⅰ,土壤有机碳、全氮、全磷和全钾含量表现为崩岗Ⅲ崩岗Ⅱ≈崩岗Ⅰ。从集水坡面至沟道出口,土壤容重和砂粒含量呈增加→减少→增加趋势,粉粒和黏粒含量呈降低变化趋势,集水坡面和崩积体有机碳、全氮、全磷和全钾含量明显高于其他部位,在崩壁顶部及沟道出口最低。从集水坡面至沟道出口,铵态氮和硝态氮含量呈先增加后减少的态势,速效钾含量呈"V"型变化态势,最低值出现在崩壁底部,速效磷和pH呈增加态势。本研究表明,崩岗系统内土壤结构和土壤养分含量总体水平较差,不同侵蚀部位土壤性质存在明显空间差异,自然植被恢复过程对土壤特性有一定的改良效应。     

植被恢复对侵蚀红壤可溶性有机质含量及光谱学特征的影响

为了解植被恢复对侵蚀红壤可溶性有机质含量及结构特征的影响, 以福建省长汀县河田镇植被恢复后的侵蚀红壤及对照裸地为研究对象, 对两试验地0-60 cm深土壤中可溶性有机质的含量及光谱学特征进行了比较研究。结果表明: 侵蚀红壤植被恢复后, 土壤可溶性有机碳含量显著提高, 在土表到60 cm深度的6个10 cm土层中, 植被恢复土壤可溶性有机碳含量分别提高为对照裸地相应土层的5.6、4.7、4.6、3.1、2.4及2.2倍。可溶性有机氮含量在两试验地之间的差异在各土层中不一致。植被恢复各土层侵蚀红壤可溶性有机质的芳香化指数显著高于对照裸地, 荧光发射光谱腐殖化指数略高于对照裸地, 植被恢复后的侵蚀红壤与对照裸地间荧光同步光谱腐殖化指数无明显差异。荧光同步光谱图中, 两试验地侵蚀红壤可溶性有机质的吸收主要为类蛋白质及芳香性脂肪族荧光基团的吸收。傅里叶红外光谱结果显示, 与对照裸地相比, 植被恢复后的侵蚀红壤土壤可溶性有机质中官能团种类更多, 且含有更多芳香碳及羧基碳。两试验地土壤可溶性有机质均表现为芳香化及腐殖化程度随土层的加深而降低。相关性分析显示, 土壤可溶性有机质的芳香化及腐殖化指数与土壤碳氮总量有极显著正相关关系。总之, 侵蚀红壤经植被恢复后, 土壤可溶性有机碳含量及可溶性有机质的芳香化指数显著提高, 可溶性有机质的腐殖化指数略有增大, 可溶性有机质结构更复杂, 更不易被分解, 因此有利于土壤肥力的恢复。     

黄土高原的侵蚀及其防治对农田生态环境的影响

黄土高原是我国侵蚀最严重的地区,在53万平方公里总面积中,80%以上面积有水土流失。流失严重区每年每平方公里冲刷土壤5,000—15,000吨,陕北、晋西最大可达40,000吨。地表冲刷深0.5—1.5厘米/年,最大达4厘米/年。如此强烈的侵蚀,改变地形,吞毁农田,破坏植被,冲走养分,使农田生态环境急剧变劣,生物量降低。侵蚀是影响黄土高原农田生态环境及生态系统的一个重要因子。     

祁连山典型流域谷地植被斑块演变与土壤性状

植物群落演变与土壤性状变化之间的相互作用和过程研究对于认识生态系统结构和功能演变有着重要的意义.对祁连山谷地灌丛草甸退化演变过程中植物群落物种组成、土壤物理和化学性状特征、及土壤与植被的相互作用进行了研究,结果表明,在祁连山谷地阴坡林线以下较小的空间范围,植被斑块由金露梅群落向金露梅-马蔺群落斑块和马蔺群落斑块演变,植被盖度降低,但物种多样性增加.不同植被斑块之间土壤水分有显著的梯度变化,土壤水分的变化导致植被的退化演替.植被斑块的演变导致土壤性状的明显分异,从金露梅灌丛斑块向金露梅-马蔺群落斑块和马蔺群落斑块演变,土壤容重显著增加,土壤团聚体组成由大粒级的大团聚体(》1mm)破碎为小粒级的大团聚体(1-0.25mm)和微团聚体(《0.25mm),团聚体稳定性降低,表明土壤结构的退化;土壤有机碳含量下降了31.2%和55.9%,干筛各粒级土壤团聚体中有机碳含量金露梅-马蔺群落斑块和马蔺群落斑块显著低于金露梅斑块,土壤团聚体平均重量粒径与有机碳含量存在显著相关,植被退化演变中土壤有机碳的损失部分地由于团聚体的破碎引起;土壤全氮和有效氮不同斑块之间也有显著的差异,植被斑块退化演变使氮的有效性降低;但磷、钾养分对植被变化的响应不敏感.植被的退化演变使土壤团聚体破碎、土壤结构退化,有机碳和全氮含量下降,使其抗侵蚀能力和水源涵养功能显著降低,又进一步加速植被的退化演替.在气候变暖的趋势下,马蔺斑块将进一步向林线逼近,灌丛草甸植被将会进一步退化和萎缩.     

黄土区草本植被根系与土壤垂直侵蚀产沙关系研究

为了系统揭示植被根系对径流侵蚀产沙的影响,采用土钻法对草地植被根系分布特征进行系统调查,采用分层冲刷的方法对黄土高原草地土壤不同坡度、不同流量条件下的侵蚀产沙特征进行了研究。结果表明不同立地上的植被根系都表现出了随着土层深度增加而减少的趋势。分层冲刷的试验结果表明在土壤表层,植被根系对侵蚀产沙的影响是占主导地位的;而当土层超过一定深度后,根系的分布数量减少,不同流量和坡度下的深层土壤侵蚀产沙量明显增加,根系提高土壤抵抗径流侵蚀产沙的能力受到了限制。同时随着土层深度的不断加大,坡面上径流侵蚀的形态也在发生变化,逐渐从面蚀向细沟侵蚀发展。结合对草地植被根系生物量垂直分布特征的研究,证明土壤侵蚀产沙的这种变化是与草本植被根系的分布特征密切相关的。通过进一步分析植被根系分布特征和土壤垂直侵蚀产沙之间的联系,建立了草地植被根系生物量与土壤垂直侵蚀产沙特征之间的定量关系。     

植被与侵蚀控制:坡面生态工程基本原理探索

在与近地面大气和与表层至浅层土壤的相互作用中,植被表现出相应的水文－机械效应,形成一定的抗蚀护坡工程性状,坡面生态工程把这些植被性状和土壤结合起来,用于斜坡的保护工程,在过去几十年中,随着对植被－土壤相互作用及其侵蚀控制意义认识的深化,使坡面生态工程应用得到迅速发展,成为生态环境建设和工程坡面保护的重要手段,这个生态学途径的一个重要内容是“土壤－植被系统”的概念,以及由此推导出的系统生物学和工程学     

我国植被水土保持功能研究进展

 我国植被水土保持功能的研究可以概括为以下3个主要方面：1)植被水土保持功能的对比研究： 通过实地对比观测植被覆盖地与对照地（裸地、农耕地等）的径流量、土壤侵蚀量等,研究植被的减水减沙效益。研究表明,天然植被具有强大的水土保持功能,并呈现出林>灌>草的规律;人工植被水土保持功能的发挥则受到多种因素的影响,呈现出较复杂的情况。2)植被保持水土的机理研究：雨滴击溅和径流冲刷是水土流失的动力,通过分析植被削减降雨和径流动能的过程,来揭示植被水土保持功能的内在机理。研究表明,植被外在的水土保持功能是其内部各个垂直层     

Effects of vegetation cover and precipitation on the process of sediment produced by erosion in a small watershed of loess region

With growing concerns over changes of the living environment and ecological environment, more and more scholars have focused their researches on understanding how vegetation covers and atmospheric conditions respond to soil erosion in watersheds. Former studies show that both the natural factors such as precipitation, vegetation, slope of terrain, soil properties and human activities are the main factors to affect the amount of sediment produced by erosion in the watershed, and there are special conditions of climate and soil that are unique to loess areas for water and soil conservations. Thus the relationships between soil erosion and vegetation and precipitation are very complicated and interesting. As a loess area, the Lüergou watershed with the area of 12.1 km2 lies in west of China. The watershed was a key area of high water and soil erosion forty years ago, but the area of vegetation cover has become larger because of highly effective methods of water and soil conservation. In the factors affecting the amount of sediment produced by erosion in the study area, which is more important for soil erosion: vegetation cover or precipitation? The experts, community has discussed this question for a long time. And the Lüergou watershed has become the natural and ideal test watershed. Based on water observation data, climate data and NOAA/AVHRR NDVI images collected from 1982 to 2000 in the Lüergou watershed of loess areas, analyses of the correlation and multi-variable regression were used to discuss the relationships among the amount of sediment produced by erosion, water indexes, precipitation factors and vegetation cover. The conclusions showed that with the increase of precipitation indexes and the decrease of plant indexes, and the amount of sediment produced by erosion in the study area would become larger. In order to distinguish the influences of erosion due to human activity and natural factors, the paper introduced multi-variable regression method by standardization data to determine the relative contributing ratio to soil erosions in the study area. The conclusions showed that the contributing ratio of vegetation cover and precipitation changes were 45.7% and 54.3%. It was obvious that the influences of precipitation were larger than those of vegetation for the soil erosion in the study area.     

Effects of vegetation cover and precipitation on the process of sediment produced by erosion in a small watershed of loess region

With growing concerns over changes of the living environment and ecological environment, more and more scholars have focused their researches on understanding how vegetation covers and atmospheric conditions respond to soil erosion in watersheds. Former studies show that both the natural factors such as precipitation, vegetation, slope of terrain, soil properties and human activities are the main factors to affect the amount of sediment produced by erosion in the watershed, and there are special conditions of climate and soil that are unique to loess areas for water and soil conservations. Thus the relationships between soil erosion and vegetation and precipitation are very complicated and interesting. As a loess area, the Lergou watershed with the area of 12.1 km² lies in west of China. The watershed was a key area of high water and soil erosion forty years ago, but the area of vegetation cover has become larger because of highly effective methods of water and soil conservation. In the factors affecting the amount of sediment produced by erosion in the study area, which is more important for soil erosion: vegetation cover or precipitation? The experts, community has discussed this question for a long time. And the Lergou watershed has become the natural and ideal test watershed. Based on water observation data, climate data and NOAA/AVHRR NDVI images collected from 1982 to 2000 in the Lergou watershed of loess areas, analyses of the correlation and multi-variable regression were used to discuss the relationships among the amount of sediment produced by erosion, water indexes, precipitation factors and vegetation cover. The conclusions showed that with the increase of precipitation indexes and the decrease of plant indexes, and the amount of sediment produced by erosion in the study area would become larger. In order to distinguish the influences of erosion due to human activity and natural factors, the paper introduced multi-variable regression method by standardization data to determine the relative contributing ratio to soil erosions in the study area. The conclusions showed that the contributing ratio of vegetation cover and precipitation changes were 45.7% and 54.3%. It was obvious that the influences of precipitation were larger than those of vegetation for the soil erosion in the study area.     

土壤呼吸的影响因素及全球尺度下温度的影响

土壤呼吸是指土壤释放ＣＯ２的过程,主要由土壤微生物和根系产生。作为一个复杂的生态学过程,土壤呼吸在受到植被,微生物等生物因素影响的同时,也受到了温度,湿度、ｐＨ值等环境因素的作用,并且随着人类影响的增强,人为因素的作用也越来越大。根据已有工作,讨论了影响土壤呼吸的主要影响因素及其相互关系,分析了全球范围内湿润地区森林植被的土壤呼吸与纬度的关系以及土壤呼吸与年均温的关系,得出了全球范围的Ｑ１０值为１     

水热积指数的估算及其在中国植被与气候关系研究中的应用

试图利用大气年平均气温、年降水量、可能蒸散和土壤水分平衡之间的关系建立一个水热积指数,并应用年平均气温、年土壤水分盈亏值和水热积指数三个气候变量来限定植物群落组合,构成一个圆形的生命-气候图式。根据全国689个标准气象台站的气候资料,计算了中国8个植被地带和26个亚地带的年平均气温、年土壤水分盈亏和水热积指数,绘制了各气候指标在中国的分布图及散点图,较好表现了中国各植被类型与气候指标的关系和格局,包括寒温带针叶林、冷温带针阔叶混交林、暖温带落叶阔叶林、亚热带常绿阔叶林、热带雨林和季雨林、温带草原、温带荒漠、青藏高原高寒植被,并得到了中国各植被地带的气候指标范围及界限。通过分析可以看出,年平均气温的等值线较好地反映了中国大陆的热量梯度,经度和纬度方向的区分均较明显;年土壤水分盈亏曲线的等值线则比较零乱;综合了热量和水分差异的水热积指数等值线与热量梯度和水分梯度均有一定的对应性,与植被类型的对应也较好。这是在宏观尺度上进行的植被与气候关系研究的一种尝试。     

塔里木河中下游地区不同地下水位对植被的影响

 根据近几年塔里木河中下游地区的大量监测结果,分析了不同地下水位对植被的影响。结果显示：1)在塔里木河中下游,地下水位与植被盖度和植物种类的回归模型分别可以表示为：Y=159.32e-0.314 8X,R2=0.819 3,　p<0.01;Y=9.113e-0.162 3X,R2=0.606 7, p<0.01。2)地下水位对植被的影响在很大程度上是通过改变土壤含水率来实现的,当地下水位在1～4 m时,其回归模型为：Y=64.898e-0.515X,R2=0.727,p<0.01;当地下水位在4～12 m时,Y=21.147e-0.178X,R2=0.658,p<0.01。当地下水位在3.5～4.0 m时,土壤含水率出现明显变化,因此认为3.5 m是塔里木河中下游地区草本植被生态恢复的最低水位。3)通过胡杨叶脯氨酸(Pro)和脱落酸(ABA)在不同水位条件下的含量变化,可以认为引起胡杨水分胁迫的地下水位出现在5.0 m。其后随着水位的降低,胡杨脱落酸的积累更加明显,地下水位与胡杨叶脱落酸含量可以表示为：Y=0.703 5e0.408X,R2=0.830 4, p<0.01。4)通过塔里木河下游输水后的植被调查,当地下水位出现明显升高后,植被的地表生态响应非常明显,乔灌草植被在水位升高至不同水位后均出现相应的变化,说明以上的分析是符合实际的。     

Research progress on the effects of soil erosion on vegetation

The relationship between vegetation and soil erosion deserves attention due to its scientific importance and practical applications. A great deal of information is available about the mechanisms and benefits of vegetation in the control of soil erosion, but the effects of soil erosion on vegetation development and succession is poorly documented. Research shows that soil erosion is the most important driving force for the degradation of upland and mountain ecosystems. Soil erosion interferes with the process of plant community development and vegetation succession, commencing with seed formation and impacting throughout the whole growth phase and affecting seed availability, dispersal, germination and establishment, plant community structure and spatial distribution. There have been almost no studies on the effects of soil erosion on seed development and availability, of surface flows on seed movement and redistribution, and their influences on soil seed bank and on vegetation establishment and distribution. However, these effects may be the main cause of low vegetation cover in regions of high soil erosion activity and these issues need to be investigated. Moreover, soil erosion is not only a negative influence on vegetation succession and restoration, but also a driving force of plant adaptation and evolution. Consequently, we need to study the effects of soil erosion on ecological processes and on development and regulation of vegetation succession from the points of view of pedology and vegetation, plant and seed ecology, and to establish an integrated theory and technology for deriving practical solutions to soil erosion problems.     

Research progress on the effects of soil erosion on vegetation

The relationship between vegetation and soil erosion deserves attention due to its scientific importance and practical applications. A great deal of information is available about the mechanisms and benefits of vegetation in the control of soil erosion, but the effects of soil erosion on vegetation development and succession is poorly documented. Research shows that soil erosion is the most important driving force for the degradation of upland and mountain ecosystems. Soil erosion interferes with the process of plant community development and vegetation succession, commencing with seed formation and impacting throughout the whole growth phase and affecting seed availability, dispersal, germination and establishment, plant community structure and spatial distribution. There have been almost no studies on the effects of soil erosion on seed development and availability, of surface flows on seed movement and redistribution, and their influences on soil seed bank and on vegetation establishment and distribution. However, these effects may be the main cause of low vegetation cover in regions of high soil erosion activity and these issues need to be investigated. Moreover, soil erosion is not only a negative influence on vegetation succession and restoration, but also a driving force of plant adaptation and evolution. Consequently, we need to study the effects of soil erosion on ecological processes and on development and regulation of vegetation succession from the points of view of pedology and vegetation, plant and seed ecology, and to establish an integrated theory and technology for deriving practical solutions to soil erosion problems.     

干旱半干旱区坡面覆被格局的水土流失效应研究进展

植被恢复与建设是控制水土流失的重要措施.在干旱半干旱地区,植被在空间上的分布呈现离散特征,在坡面上形成的裸地-植被镶嵌和植被条带分布等覆被格局对水土流失过程具有重要影响.覆被格局与水土流失关系研究是景观生态学格局与过程研究的重要内容.从植被斑块、坡面覆被格局对水土流失的影响与耦合覆被格局与水土流失的手段和方法三个方面对国内外相关研究进行总结分析.从中发现,植被类型、层次结构和形态特征是植被斑块尺度上影响径流泥沙的关键因素;不同覆被类型的产流产沙特征与覆被格局的准确描述是研究覆被格局水土流失效应的重要基础;坡面覆被格局对水土流失的影响关键在于其改变了径流泥沙运移和汇集的连续性,应重点关注径流泥沙源汇区的连通性和空间分布在水土流失中的作用;以坡面的精确覆被制图为基础,建立基于水土流失过程的覆被格局指数和耦合格局信息的径流与侵蚀模型是定量研究覆被格局影响的有效手段.今后应加强以下研究:以动态系统的观点研究覆被格局的变化对水土流失的影响,系统理解覆被格局与水土流失之间的相互联系与反馈机制,探讨两者间动态关系随尺度变化的规律性并发展尺度上推方法;构建过程意义明确且简单实用的格局指数,将覆被格局与水土流失过程有机联系起来;发展覆被格局的动态信息与产流产沙过程相结合的水文模型,加强对格局与径流泥沙反馈系统的耦合,建立真正意义上的覆被格局-水土流失过程耦合模型.     

植被与水土流失关系研究进展

水土流失是世界性的环境问题之一,对人类社会可持续发展构成威胁,控制水土流失成为迫切需要,有许多水土流失控制措施,而生物措施尤其植被一直是人们研究的焦点.根据前人的研究,从斑块、坡面和流域/区域尺度总结了植被与水土流失的关系.斑块尺度植被对降雨和径流侵蚀能量具有很大的减弱或消除作用,可以改变植株底部的土壤性质,改善其结构,进而降低土壤可蚀性,增加入渗能力,从而减轻土壤侵蚀程度.不同植被类型、植被的不同层次结构,不同植被的形态结构具有不同的土壤侵蚀控制作用.坡面尺度主要从坡位、坡度、坡向对植被生长和分布格局的影响、对水土流失过程和格局的影响以及裸地-植被镶嵌格局、植被的条带格局对水土流失的影响和反映水土流失过程的景观格局指数的构建等方面进行了研究.更多是从植被恢复及其水土流失效应方面进行了探讨,为退化生态系统恢复和格局设计提供了极其有用的信息.流域/区域尺度植被与水土流失的关系更大程度上受到气候、地貌特征的影响,因此研究多从一定气候条件控制的土地覆盖（植被覆盖）及其格局的水土流失效应方面进行的.由于大尺度监测非常困难,研究多从遥感监测、GIS集成和模型模拟方面开展,是流域、区域等大尺度生态安全格局设计的有力支持.前人的研究为生态环境建设和保护提供了大量参考信息,但仍有一些问题需要进一步探讨,对此进行了初步的概括和归纳,希望能够对植被和水土流失关系的研究起到一定促进作用.